Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Nitrogen fixation is a process where N2 (atmospheric nitrogen) is converted into NH3 (ammonia). This process makes atmospheric nitrogen accessible to living organisms.
Related terms
Nitrification: The biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of these nitrites to nitrates.
Denitrification: The process by which bacteria in soil and water transform nitrate ions back into nitrogen gas, returning it to the atmosphere.
Legumes: A type of plant such as peas and beans that have nodules on their roots containing bacteria capable of nitrogen fixation.